Coast FIRE is the moment your invested balance is large enough to grow into your full retirement number on its own - so you can stop adding new money and let compounding finish the job. If your goal is $1,000,000 by age 65 and you assume a 5% real return, you only need about $181,290 invested at age 30 or $231,377 at age 35 to coast the rest of the way without saving another dollar. You still have to work enough to cover your living expenses, but you no longer have to fund retirement on top of them. This guide shows the Coast FIRE number by age, the formula behind it, and exactly how to check whether you have already hit it. Run your own figures in the free FIRE calculator.
Coast FIRE is the gentlest milestone on the path to financial independence. Full FIRE means never working for money again; Coast FIRE just means you have pre-funded retirement early enough that time does the rest. It is the difference between sprinting and downshifting - and for many people, it arrives a decade or more before full FIRE.
The Coast FIRE formula
Your Coast FIRE number is your future retirement target discounted back to today by your expected return and the years until you retire.
Coast number = FIRE number / (1 + r)^n
Here the FIRE number is the full portfolio you will need (annual spending times 25 at a 4% withdrawal rate), r is your expected real annual return, and n is the number of years until traditional retirement. Because the balance compounds untouched for decades, a relatively modest sum today turns into the full target later. The earlier you reach the Coast number, the smaller it is - time is doing more of the work.
Coast FIRE number by age
The table below shows how much you need invested today to coast to two common targets by age 65, assuming a 5% real return and no further contributions. The 5% figure is a reasonable after-inflation planning return for a diversified stock portfolio, which keeps the whole calculation in today's dollars.
| Your age now | Years to 65 | Coast to $1.0M (≈$40k/yr) | Coast to $1.25M (≈$50k/yr) |
|---|---|---|---|
| 25 | 40 | $142,046 | $177,557 |
| 30 | 35 | $181,290 | $226,613 |
| 35 | 30 | $231,377 | $289,222 |
| 40 | 25 | $295,303 | $369,128 |
| 45 | 20 | $376,889 | $471,112 |
Notice the steep reward for starting early. A 25-year-old needs only about $142,000 to coast to a million by 65, while a 45-year-old needs $377,000 for the same target - more than two and a half times as much, because they have half as many years of compounding left. Coast FIRE is the single strongest argument for front-loading your investing in your twenties and early thirties.
How return assumptions change the number
The Coast number is highly sensitive to the return you assume, because that rate compounds over decades. The table below holds the target at $1,000,000 and the age at 35 (30 years to 65), and varies only the real return.
| Real annual return | Coast number at 35 |
|---|---|
| 4% | $308,319 |
| 5% | $231,377 |
| 6% | $174,110 |
| 7% | $131,367 |
Going from a 4% to a 6% assumption nearly halves the Coast number, which is exactly why you should be conservative here. If you declare Coast FIRE based on an optimistic 7% real return and the market delivers 4%, you will arrive at 65 with far less than planned. A safer approach is to use a modest real return and treat any outperformance as a bonus. The compound interest calculator lets you stress-test different rates, and the Rule of 72 gives a quick check: at a 5% return money doubles about every 14 years, so a balance roughly doubles 2.5 times over 35 years.
The other side: what your current balance coasts to
You can also run the math forward. Suppose you have $200,000 invested at age 30 and stop contributing. At a 5% real return, here is what it grows into - and the inflation-adjusted income it would support at a 4% withdrawal rate - depending on when you tap it.
| Retire at | Balance (5% real) | Income at 4% |
|---|---|---|
| 50 | $530,660 | $21,226/yr |
| 55 | $677,271 | $27,091/yr |
| 60 | $864,388 | $34,576/yr |
| 65 | $1,103,203 | $44,128/yr |
The same $200,000 supports roughly twice the income if you let it coast to 65 instead of 50 - the last decade of compounding is the most powerful, because it is working on the largest balance. This is why Coast FIRE pairs naturally with a longer working life at a lower-stress job: every extra year you delay drawing down dramatically lifts the income that nest egg can sustain. Track your invested total with the net worth calculator and model the growth with the investment calculator.
Coast FIRE vs Barista FIRE: a quick distinction
Coast FIRE means your retirement savings are already on autopilot and your job only needs to cover today's living costs. Barista FIRE is a close cousin: you work part-time mainly for the income and often the health benefits, while drawing a little from your portfolio to fill the gap. The shared idea is that once your retirement number is pre-funded, you can trade a high-paying, high-stress job for work that simply pays the bills. Both rely on the same expense-based target - find that target first with the FIRE calculator, then decide how much, if any, work income you still want.
How to check if you have hit Coast FIRE
You can confirm your status in a few minutes with numbers you already have.
- Set your full retirement number. Multiply your expected annual retirement spending by 25 for a 4% withdrawal rate. For $40,000 a year that is $1,000,000.
- Pick a conservative real return. Use about 5% after inflation so the calculation stays in today's dollars and you are not relying on an optimistic market.
- Count the years to retirement. Subtract your current age from your traditional retirement age, often 65, to get the number of compounding years.
- Discount the target back to today. Divide your retirement number by (1 + return) raised to the power of those years. The result is your Coast FIRE number.
- Compare it to your invested balance. If your current portfolio meets or exceeds that figure, you have hit Coast FIRE. Confirm the growth path in the FIRE calculator by setting your annual contribution to zero.
What Coast FIRE does not solve
- It does not cover today's expenses. Coast FIRE pre-funds your sixties, not your forties. You still need income to live on until you start drawing the portfolio.
- It assumes you truly leave the money alone. Coasting only works if you do not withdraw or pause investing during downturns. Selling in a dip breaks the projection.
- It is sensitive to your return assumption. An optimistic rate makes the Coast number look smaller than it safely should be. Use a conservative real return and re-check periodically.
- It still faces the pre-Medicare healthcare gap if you fully stop working. Coast FIRE usually assumes you keep working part-time, which often keeps benefits in play.
For plain-language guidance on long-term investing and compounding that underpins the Coast FIRE math, the U.S. Securities and Exchange Commission (Investor.gov) is a reliable reference.
The bottom line
Coast FIRE is the point where your invested balance can grow into your full retirement number on its own, freeing you to stop saving and work only to cover present-day costs. At a 5% real return, coasting to a $1,000,000 retirement by 65 takes about $181,000 at age 30 or $377,000 at age 45 - the earlier you reach it, the smaller the number, because compounding has more time to work. Keep your return assumption conservative, leave the money untouched, and remember Coast FIRE still requires income for today. Set your full target and test a zero-contribution path in the FIRE calculator, then explore the retirement hub or the homepage for the rest of the toolkit.
Try it yourself
Run your own numbers in the free FIRE Calculator — instant, private, no sign-up.
Open the FIRE Calculator →Frequently asked questions
- What is Coast FIRE?
- Coast FIRE is the point where your invested balance is large enough to grow into your full retirement number on its own, with no further contributions. You still work to cover current living expenses, but you no longer need to save for retirement. For a $1,000,000 goal at 65 with a 5% real return, you reach Coast FIRE at roughly $181,000 invested by age 30.
- How do I calculate my Coast FIRE number?
- Divide your full retirement number by (1 plus your expected real return) raised to the power of the years until you retire. For a $1,000,000 target, a 5% real return, and 30 years to 65, that is $1,000,000 / 1.05^30, or about $231,377. The earlier you run it, the smaller the number, because compounding has more years to work.
- How much do I need for Coast FIRE at 30?
- To coast to a $1,000,000 retirement by age 65 at a 5% real return, you need about $181,290 invested at age 30. For a larger $1,250,000 target (roughly $50,000 a year in retirement), the figure rises to about $226,613. Both assume you stop contributing and leave the balance untouched until retirement.
- What return should I assume for Coast FIRE?
- Use a conservative real return of around 5% after inflation, because the number is very sensitive to this assumption. At a 35-year-old's 30-year horizon, a 4% return requires $308,319 to coast to $1,000,000, but a 6% return requires only $174,110. An optimistic rate makes the Coast number look smaller than it safely should be, so leave room for weaker markets.
- What is the difference between Coast FIRE and Barista FIRE?
- Coast FIRE means your retirement savings are fully pre-funded and your job only needs to cover today's expenses, with no portfolio withdrawals yet. Barista FIRE means you work part-time for income and often health benefits while drawing a little from your portfolio to fill the gap. Both let you leave a high-stress job, but Barista FIRE taps the portfolio early while Coast FIRE leaves it untouched.
- Can I really stop saving once I hit Coast FIRE?
- Yes, you can stop saving for retirement specifically, but you must still earn enough to cover current living costs and leave the invested balance completely untouched. Coasting only works if you do not withdraw or pause investing during downturns, since selling in a dip breaks the projection. If you fully stop working before 65, also budget for the pre-Medicare healthcare gap.
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